1. Field of the Invention
The present invention relates to spectrometer readout systems and, more particularly, is directed toward high-speed sequential readout spectrometer systems.
2. Description of the Prior Art 2. A direct reading spectrometer is an apparatus adapted to indicate automatically the chemical composition of a specimen for determining the intensity distribution of radiation of characteristic wavelengths emitted by the specimen under excitation. Typically, a direct reading spectrometer comprises an entrance slit that transmits radiation from an electrically excited specimen against a diffraction grating that disperses the radiation into a spectrum. A spectrometer also includes a plurality of exit slits arrayed at selected spaced intervals for transmitting the radiation of preselected wavelengths to photocell channels in order to determine the differing intensities of the radiation at these wavelengths.
In an automatic spectrometer, described in U.S. Pat. No. 3,531,202, the output of a series of photomultiplier tubes positioned to monitor selected spectral lines is temporarily stored on capacitors. An analog to digital converter converts the stored voltages into digital form which is logarithmically related to a known signal and an unknown signal. The output of the converter, the log discharge time period, is measured and stored by a time register scaler. A computer and programmer are operatively connected to the converter and the register with the computer being adapted to provide an output which is a representation of the direct percentage of concentration of the monitored element. The programmer controls the sequence operation of the system and also provides an output to a disc or printer.